The present invention relates generally to broadband and wireless communications and more particularly to a scheduling method for adaptive resource usage in orthogonal frequency-division multiple access OFDMA wireless relay networks.
There has been an increasing demand to provide ubiquitous mobile access for a multitude of services ranging from conventional data to real-time streaming applications. To meet such requirements, existing cellular systems need enhancement to provide improved data rates and connectivity. Adding less sophisticated and less expensive “relay” stations (RS) to the network helps improve the throughput and coverage in the network.
Unlike conventional cellular networks, the throughput performance of relay networks is closely tied to maximizing the network flow (throughput capacity) over the two hops of the network. This is however dependent on how well the available OFDMA resources are utilized on the two hops of the network. The upcoming relay standards in next generation broadband access technologies like WiMAX allow for two design features to accomplish this: (i) adaptive frame segmentation, and (ii) access hop reuse. While prior art has focused on designing scheduling algorithms for leveraging diversity and reuse across hops, they have not focused on designed scheduling methods that optimize adaptive frame segmentation and reuse within the access hop to efficiently utilize OFDMA resources.
Prior scheduling works in OFDMA relays have focused largely on leveraging diversity gains. One prior work considered spatial reuse across relay and access hops, but did not consider reuse within the access hop. Further, none of these works have studied the impact of adaptive frame segmentation coupled with access hop reuse on the network capacity through design of efficient scheduling algorithms with performance guarantees.
Accordingly, there is a need for an improved unicast throughput performance of relay-assisted OFDMA cellular networks through efficient usage of OFDMA resources.